Climate Science Glossary

Term Lookup

Settings

Use the controls in the far right panel to increase or decrease the number of terms automatically displayed (or to completely turn that feature off).

Term Lookup

Term:

Settings

Beginner Intermediate Advanced No DefinitionsDefinition Life:

All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

Posted on 10 March 2011 by ClimateHawk

One climate myth found on the internet, propagated by Anthony Watts, is that James Hansen erroneously predicted the West Side Highway would be underwater by 2008. James Hansen made his statement in response to a question by Bob Reiss, a journalist and author, in 1988. A close examination of the interview reveals Hansen did not, in fact, predict that the West Side Highway would be underwater in 20 years. Bob Reiss reports the conversation as follows:

"When I interviewe­­d James Hansen I asked him to speculate on what the view outside his office window could look like in 40 years with doubled CO2. I'd been trying to think of a way to discuss the greenhouse effect in a way that would make sense to average readers. I wasn't asking for hard scientific studies. It wasn't an academic interview. It was a discussion with a kind and thoughtful man who answered the question. You can find the descriptio­­n in two of my books, most recently The Coming Storm."

James Hansen reports the conversation as follows:

"Reiss asked me to speculate on changes that might happen in New York City in 40 years assuming CO2 doubled in amount."

The book The Coming Storm and the salon.com article are different. In The Coming Storm the question includes the conditions of doubled CO2 and 40 years, while the salon.com article which is quoted by skeptics does not mention doubled CO2, and involves only 20 years.

To understand the discrepancy between these two published accounts, it helps to look at the timeline of events. The original conversation was in 1988. Ten years later, referring to his notes, Bob Reiss recounted the conversation in his book The Coming Storm. James Hansen confirmed the conversation and said he would not change a thing he said. After the book was published, Bob Reiss was talking to a journalist at salon.com about it. As he puts it,

"although the book text is correct, in remembering our original conversation, during a casual phone interview with a Salon magazine reporter in 2001 I was off in years.”

We can check back in 2028, the 40 year mark, and also when and if we reach 560 ppm CO2 (a doubling from pre-industrial levels). In the meantime, we can stop using this conversation from 1988 as a reason to be skeptical about the human origins of global warming.

Comments

The diffidence of the conclusion of this post typifies why we are losing this debate.

Why, you make it sound like Hansen said the highway would be under water in 40 years given doubled CO2 instead of in only 20 years. That still sounds implausible, not at all helpful to getting people to take the issue and the predictions seriously.

I'm not sure how prone this particular highway is to flooding. Maps of sea level rise indicate that 1 meter would put parts of the road underwater. A doubling of CO2 gets us there, but the timeframe for when we get to 560 ppm and when this occurs is probably longer than another 20 years from now. The timeframe isn't Hansen's prediction though. He was asked what a doubling of CO2 scenario would look like. It's the reporter that threw out 40 years.

You need to take into account tides, atmospheric pressure, storms etc.

Hence occasionally a small sea level rise, combined with tides etc, will result in flooding.

The other point is that by not dealing with emissions now, you are offloading the cost of flood adaptation onto future generations. Increased warming means that sea levels will continue to rise, they won't stop once they reach a 'magic' number quoted in the press/media.

Didn't Hansen's conversation in 1988 precede a major reconstruction of the West Side Highway? I had heard that at least part of the reason for this was that it was flood-prone. But I haven't lived in NY since the 60s, so maybe I heard wrong.

According to the quotes above, they just said "with doubled CO2" or "assuming CO2 doubled in amount". They didn't say "from pre-industrial levels". Thus it could be even taken as doubling from 1988 levels.

I am so tired of the right's penchant for equating predictions with prophecies. There are always conditions inherent in predictions that if changed outside the assumed or stated limits nullifies the prediction. It becomes neither right nor wrong.

I thought I'd post a link to a webcam of West Side Highway so people could follow the progress of the rising water. I got this one which seems to show an aircraft carrier travelling down the road. It looks like we're too late!

For the record, here's the Sea Level Rise Explorer map of Manhattan. The red strip along the southwest side of the island is the West Side Highway. Red is just a bit above current sea level. The PATH trainyards just south of 34th St are a particularly low point; the aircraft carrier referred to is part of a museum a few blocks north.

The GISS office is uptown and uphill a bit (in the green), but with a good view of events. If you zoom the map, look for Broadway and 112St, about 1000' off the river.

Charlie - if sealevel stays are 3-4mm per year, then I would say no problem. We can adapt fast enough. If it exceeds 10mm/year, that is another story but that is the prediction for latter part of this century. Frankly worrying about Manhattan seems a little twee compared to issues of storm surge, erosion and salt-invasion on the big deltas of the world.

Hank, maybe you should check out the NOAA San Fransisco sea level charts.
http://tidesandcurrents.noaa.gov/sltrends/sltrends_station.shtml?stnid=9414290
I know you are concerned about the models, but for 30 years, since 1980, there has been appreciable rise in sea level. 8 inches per century, same old, same old.

That would be 1-7 metres (seawalls are 1.5M above SL at their minimum in the south of the island). At it's worse SLR is expected to be in the region of 10-20cm by 2028. It's still presently 3.4mm/yr and has been for the past 20 years. It's going to have to average more than 3 times that amount from now on to hit the 20cm mark by 2028. I suspect sea level isn't necessarily the issue here rather suspected increase in storm severity.

Has anybody read the extended quote from Hansen. Honestly this reads like post-apocalyptic SF to me.

"The West Side Highway [which runs along the Hudson River] will be under water. And there will be tape across the windows across the street because of high winds. And the same birds won't be there. The trees in the median strip will change." Then he said, "There will be more police cars." Why? "Well, you know what happens to crime when the heat goes up."

(this is from the Salon interview with Reiss so take it with as big a pinch of salt as you like but I don't see anybody running to correct this part)

"A study in Nature Geoscience in March warned that warmer water temperatures could shift ocean currents in a way that would raise sea levels off the Northeast [USA] by about 8 inches (20 cm) more than the average global sea level rise. But it did not include the additional impact of Greenland's ice, which at moderate to high melt rates would further accelerate changes in ocean circulation and drive an additional 4 to 12 inches (about 10 to 30 cm) of water toward heavily populated areas of northeastern North America on top of average global sea level rise. More remote areas in extreme northeastern Canada and Greenland could see even higher sea level rise."

So it may well be that the east coast of N. America experiences a greater increase in sea level than other areas will.

If I were a betting man, my money would be on Hansen. His prediction may not be perfect, but it will probably be pretty close to the mark.

00

Moderator Response: [DB] Nice study. Similar to the Bamber et al study in Science 2009, which found a 25% greater impact from SLR on the US Eastern Seaboard cities than the global average.

So to be pedantic (or scientific) about this if the issue is storm surge then what are the chances that anybody looking out of the window from the GISS building in 2028 will witness flooding from an extreme weather event? Will 1:100 year events become 1:25 years events? Or will they become annual?

Should Hansen state

"The West Side Highway [which runs along the Hudson River] will be under water"

Not even probably, likely, possibly.

Will NY city see this coming and added another metre to the seawall? If we tried to look at this scientifically I suspect Hansen is more likely in the 5% region of the curve than the 95% region and that would be accepting the IPCCs version of the science.

I know the point here is to show the sloppiness of WUWT but really shouldn't we be taking a hard look at Hansens prediction even if it's for 2028?

I took a hard look at Hansen's prediction for 2028 and discovered, he did not make a prediction for 2028 at all. He was asked in 1988, if CO2 doubles, what kind of impact would that have. He illustrated the impact of a doubling of CO2 by talking about what a meter rise in sea level would look like, he did not predict it would happen by any specific time in that interview. The 40-year period, and the 20=year period seem to have been tacked on along the way. Is it really that hard to understand the topic here? The topic is how people twisted his illustration of the impact of a hypothetical doubling of CO2 into a "prediction" of an event within a specific period of time.

I think I acknowledged that the topic is about how Watts got it wrong. But what's more important speculation by an influential climate scientist who's helping to shape the IPCCs position or a blogger? Sorry if I disagree with the ClimateHawk's (and you) about the priority and the scope of the discussion here. Given the last sentance in the article one could argue that the topic is also why we should forget about what Hansen predicted. I'm not so sure we should do that.

"In the meantime, we can stop using this conversation from 1988 as a reason to be skeptical about the human origins of global warming."

Hansen was assuming CO2 would double by 2028. Are you saying that assumption is wrong?

"Reiss asked me to speculate on changes that might happen in New York City in 40 years assuming CO2 doubled in amount"

Whether this is a prediction or speculation is irrelevant, it's helped shape the wider debate of climate science, it comes from an influencial individual in that debate. It's worth arguing the merits of it. If he still stands by what he said in 1988 (which he does) then it's well worth arguing about.

HR: increasing sea-level makes storm surges worse not more frequent. On what I imagine is hard surface in advanced country, I imagine the effect will not be large. In an area like Mekong or Ganges delta, it will be a bit tougher.

If he still stands by what he said in 1988 (which he does) then it's well worth arguing about.

It's especially worthwhile for people who can't really argue on the basic science, and are accordingly forced to personalize the issues, and create pointless distractions and fake scandals wherever possible.

Thus, no opportunity to distort Hansen's views -- or better yet, to assume some God's-eye, extratemporal position from which to declare him wrong then, now and forever -- can be passed up.

Meanwhile, "skeptics" get to churn out endless claims and predictions -- many of which are based on little more than resentment and wishful thinking, and are debunked in a matter of days, if not hours -- without losing much, if any, credibility among their peers.

I don't know what's more irritating: the hypocrisy, or the assumption that we're not attentive enough to notice it.

Looks like a story thats got altered in the retelling and not something you want to get too bogged down defending. Make the key points concisely, but mainly go on the attack.

I think I recall Watts saying ten years ago that we were entering a cooling period. Certainly various sceptics were. Clearly it hasnt happened. But all I see is you people fighting a rear guard action and getting derailed and trumped.

Phila it's not being personnal to critically examine what a scientist says about the science whether that is speculation or predictions.

If Hansen wants to acknowledge that this speculation has nothing to do with the science then I'd be happy to drop it. In fact if you and others say that this has nothing to do with science then I'll drop it. The balls in your court.

RickG #12 said: "its pretty well understood when climatologists talk about a doubling of CO2 they are referencing a doubling of the pre-industrial amount of 280 to 560"

That depends on the context. And in this case, the question wasn't posed by a climatologist, but by a journalist. Look at this abstract, for example. It just says "climate simulations with 2 × CO2". If you don't have acces to the whole paper you may asume they are working under 2xCO2 since pre-industrial levels. However, if you have the chance to dig into the actual paper, you will see that their scenario is "under 2 × CO2 (700 ppm)".

Thanks for the links. The Bounoua et al 2010 paper is interesting but also rather confusing, at least to me. They state a base line of 350 ppm and talk about doubling to 700 ppm. What is confusing is that all three of their modeled scenarios only extend 30 years. That is not anywhere realistic for a doubling of CO2. I admit that I only gave it a fast read and maybe I'm missing something.

Nevertheless, I still think the Hansen discussion is a pre industrial base line.

First, HR, Hansen's comments where clearly designed to illustrate a speculative scenario. They are not a scientific forecast. They are a spur of the moment speculation. That criticisms of such comments seems so important to deniers suggests they have nothing substantive to say about the actual science.

Second, even if we allow Hansen's comments as being a substantive scientific contribution as the deniers seem to want us to do, they are clearly obsolete. This is worse than trying to dam AR4 because The First Assessment report contained a minor error.

This does not mean it is inappropriate to compare Hansen's predictions with later events. However, to do so, you should take his published opinions (not of the cuff remarks), and you should allow the predictions to be adjusted in light of detailed knowledge in which there has been a clear advance since the prediction (such as the range of plausible values for climate sensitivity). This is not mystical prognostication, it is science.

Third, it is very unclear what is actually predicted. The most straight forward interpretation (to me) of the prediction is what would New York look like 40 years after a doubling of CO2, ie, after the effects of such a doubling had time to impact the global climate system. So, this conversation is premature anytime before 40 years after such a doubling. On current estimates, that should be some time around 2090.

RickG has the right of it. The skeptics' favorite toy, the Bounoua et al 2010 paper, must be evaluated in context: it is intended to investigate a thought model of what happens to evapotranspiration, plant growth, planetary albedo and global surface temperatures under an already doubled CO2 scenario, under which all other variables/forcings are constrained (assumes low climate sensitivity of less than 2°C, air+ocean thermal response to doubled CO2 already achieved, etc). It is a modeling study narrowly designed to evaluate an investigative line of thought only (i.e., not a forecasting model per se).

What it does not do is speak to the other multitude of other feedbacks known to exist affecting sea level rise and ice sheet response to a warming world, factors known to already be at play. As such it is of zero value with regard to the topic of this post (well, maybe when the moon is in the 7th house and Jupiter collides with Mars ☺ ...).

HR >"Hansen was assuming CO2 would double by 2028. Are you saying that assumption is wrong."

Depends-- if he was talking about CO2 equivalent as they do in the IPCC, then he might be pretty darn close. And that is part of the problem, this was an off the-cuff comment, not a formal scientific projection.

It is interesting to see the skeptics here say we can just raise the sea walls a meter and in other threads they say it is too expensive to do anything to lower CO2 emissions. How much will it cost to raise all those seawalls? Remember you have to raise the road bed also. Will you build Miami's sea walls on their beachfront? Once sea level rise really gets going after 2050 it will not be cost effective to raise the sea walls, the city will have to be moved. London is reported to be able to raise their sea walls 2 meters and then have major problems. Miami's water supply will be underwater long before then.

Has anybody on this site even read either the Watts post or the Salon article? It doesn't sound like it. After quoting the Salon article verbatim, and then posting some pictures of the GISS offices and the viewscapes available therefrom, he compares that to Hansen's admittedly vague prediction of sea level rise. Vague in the sense of how many years and how much of an increase in CO2. Fine. But a prediction, nonetheless, of flooding in New York. So, Watts concludes, "So much for local climate change predictions by the leading global authority on climate change."

How ClimateHawk can conclude that, "In the meantime, we can stop using this conversation from 1988 as a reason to be skeptical about the human origins of global warming."? It is Hansen (via Reiss) himself that brings into question the validity (or at least the prognostic abilities) of Mr. Hansen and his predictions. And, Watts is talking about local changes that Hansen himself brought up. ClimateHawk seems to think that a skeptics comments about predictions of local change are the same as a pronouncement about "human origins of global warming". Simply amazing.

"Whether this is a prediction or speculation is irrelevant, it's helped shape the wider debate of climate science"

This is a valuable insight into the denier's view of what constitutes the 'debate.' I suspect that if someone asked Dr. Hansen the time and his watch was 5 minutes slow, the deniersphere would still be trumpeting 'Hansen can't tell time!' 5 years later.

Phila it's not being personnal to critically examine what a scientist says about the science whether that is speculation or predictions.

IMO, it is indeed personal when that "critical examination" obsessively targets high-profile climate scientists, while giving far more error-prone "skeptics" a pass. The result of this approach is that someone like Hansen has to hit a bullseye 11 times out of 10, while "skeptics" aren't even required to aim at the target. (As an added bonus, they get to reject any claim about AGW that strikes them as "alarmist," which is a cute way of "winning" every debate before it properly begins.)

If you can come up with some other credible explanation for this demonstrably unbalanced approach than a desire to discredit the science by attacking individuals -- and portraying any alarming scenarios as unscientific by definition -- I'm all ears.

In fact if you and others say that this has nothing to do with science then I'll drop it. The balls in your court.

I can understand why you'd want to reduce this debate to a false dilemma. Presumably, you can understand why I reject that approach. Per Tom Curtis @39, "That criticisms of such comments seems so important to deniers suggests they have nothing substantive to say about the actual science." Which was the point of my initial comment, as well.

Actually, Phila, Hansen should be held to a higher standard. He has the titles. He gives expert testimony before congress. He is cited by NOAA, IPCC, etc. as an expert. He needs to be right all of the time. It's not "unbalanced" to expect that he be able to defend all of his positions. He shouldn't be making them if he's not sure. Otherwise, why are we paying him? Or are you admitting the uncertainty of the whole subject?

In fact, he does defend all of his positions within the scientific community. There is no error in his statement. If CO2 doubles, whenever it doubles, sea levels will rise a meter. No one doubts that. You are grasping at straws, which only shows how weak your position is.

No, that is a fallacy. Applying your logic we should not be funding the National Weather Service in the USA to issue warnings for severe weather because they are not correct 100% of the time. Yet, there is immense value in their warnings. Same goes for medical doctors-- and they get payed much, much more than does Hansen.

You are being unrealistic and are not grounded in reality. I hope you now realize the folly of your reasoning. I strongly suspect that you are placing unrealistic expectations to set someone up for a fall, just so it can reinforce your skewed perception of reality and dismiss their inconvenient findings.

I do agree that Hansen should be held to a high standard, and he is, pretty much every word he says is scrutinized. What would be disappointing (and telling) is if you did not apply your critique or skepticism equally, that is what a true skeptic would do. So I find it odd that you do not concede that Watts is misrepresenting what Hansen actually intended to communicate. And let us not be naive, Watts is embarking on an orchestrated misinformation campaign and relishes in defaming climate scientists.

Albatross all that modelling work is fine but did you look at the data presented by Charlie A in #20. If your data is correct then New York should be one of the spots on the earth were accelerating SLR should be showing up earliest. I don't see it in the on the ground data, it looks pretty much linear. When are we going to start to see this exponential growth? It's 17 years until Hansens speculation, but more generally the satellite data is still failling to show anything but a linear rise.

tomurray @43, I have read the original post at WUWT. I noticed, for example how they carefully showed the windows of the offices of not only Hansen, but also Schmidt (who was totally unconnected to the article), two men known to have received death threats. (I also read their very weak defense of that action in the comments.)

I also noticed how they are taking an ambiguous prediction from a casual interview rather than the equivalent prediction from Hansen's scientific work (which would be precise, and not in need of interpretation) as the basis of their commentary.

Finally, I also notice that you have set up a standard whereby if what Hansen has predicted for the 2090's is not fulfilled by the 2010, then his work (all of it, apparently) can be dismissed. Finding pretexts to dismiss evidence may be preferable (for some) to actually understanding the evidence. However, it does not impress.